JP2006305859A - Thermal history control unit, its operating method, and thermal printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable multi-history and high-speed printing without causing an increase in the scale of a circuit of hardware to the utmost, while making use of advantage brought about by generating a history pattern of thermal history control by using software. <P>SOLUTION: This thermal printer comprises: a thermal head interface LSI 15 which is connected to a thermal head 16; and a CPU 11, a communication control part 12, a RAM 14, and a ROM 13, which are connected to the LSI 15. The CPU 11 performs the processing of generating the history pattern for each history factor by referring to the past printed dot of the thermal printer, according to the software 131 of the ROM 13. In this case, the number of the history factors and each history timer value in one line are preset in the register of a timer circuit 152 before the printing of a line to be printed is started; the history timer values equivalent to the preset number of the history factors are sequentially expanded in the timer circuit 152; the number of times of access to the LSI 15 in one line is reduced; and the history patterns for some coming lines are generated by the software 131. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a thermal history control device, an operation method thereof, and a thermal printer, and more particularly to a thermal history control method for suppressing the influence of heat storage generated in past printing operations on dots of a line to be printed.

  A thermal printer provided with a line-type thermal head is used in various printers such as a receipt issuing printer mounted on a POS (Point Of Sales) apparatus. In the line type thermal head used in this thermal printer, a plurality of heating elements assigned to each dot of a dot row constituting print data are selectively selected based on a print command and print data transmitted from a host side such as a POS device. Thus, desired printing is performed on a printing medium such as recording paper by the heat generated by each heating element.

  In such a thermal printer, in order to suppress the influence of heat storage generated in the past printing operation on the dots of the line to be printed from now on, a part of the dot image of the line printed in the past is stored and based on this. Thermal history control for controlling the application time of the thermal head to the heating element is performed (for example, see Patent Document 1). Hereinafter, the thermal history control of the conventional example will be described with reference to the contents disclosed in Patent Document 1.

  In the conventional thermal history control, first, several lines after completion of printing are held, and past printing dots that may have an effect of heat storage on the dots to be printed are investigated. As a result, if the corresponding dot has been printed in the past, it is considered that there is an effect of heat storage compared to the case where nothing is printed, so the energization time to the thermal head is shortened. In this case, since the degree of influence of heat storage due to past printing operations varies depending on the number of past printing dots and dot positions, the past printing history is modeled according to a certain pattern, and a plurality of modeled target dots are expressed as `` history factors. And weighting each history factor in terms of time. After that, it is determined which dot has been printed at which position in the past, and the time assigned to the printed history factor is thinned out from the entire application time. An example of this is shown in FIG.

  For example, in the example shown in FIG. 6, the dot line data to be printed and the data (dot image) for the past four dot lines are stored in the memory, and the dot that forms the history factor in accordance with a certain pattern is stored. Is extracted and modeled. In the example of FIG. 6, the dots constituting the modeled history factor are the dot Ta immediately before the previous dot line and the dots Tb1 and Tb2 adjacent to the left and right of the previous dot line with respect to the dot T0 of the dot line to be printed. The dot Tb0 before the previous two dot lines and the dots Tc1 and Tc2 adjacent to the left and right, the dot Tc0 before the past three dot lines, and the dot Td before the past four dot lines (the white circles in the figure are Non-energized dots and black circles represent energized dots).

  Next, a necessary application time when nothing has been printed in the past is T, and this application time T is the dots Ta, Tb1, Tb2, Tb0, Tc1, Tc2, Divide by time distribution of Tc0 and Td. The time distribution is determined by the degree of influence of heat storage on the dots T0 to be printed by the dots Ta, Tb1, Tb2, Tb0, Tc1, Tc2, Tc0, and Td that constitute past history factors.

  For example, in the example of FIG. 6, when the dot Ta before the previous dot line is compared with the dot Tc0 before the previous three dot lines and the dot Tc0 before the previous three dot lines with respect to the dot T0 of the dot line to be printed from now on, Since Ta has a greater effect of heat storage on the dot T0 to be printed from now on, in general, a larger time is allocated to the dot Ta than to the dot Tc0.

  After that, it is investigated which history factor has been printed in the past for the dot T0 to be printed, and “0” is not printed in the past as data (OFF) that does not energize the history factor that has been printed in the past. For the history factor, “1” is calculated as energized data (ON), and the calculation result is set. As a result, the application time T can be obtained by thinning out the time assigned to the history factor printed in the past from the application time T corresponding to the thermal energy in which the thermal paper is purely colored by ignoring the history control. Adjust.

For example, in the example of FIG. 6, there are three dots printed in the past, Tb2, Tb0, and Tc0, with respect to the dot T0 to be printed. In other words, compared to the case where nothing has been printed in the past, it is considered that heat storage has occurred due to the application of these three locations at this time,
Application time = T− (Tb2 + Tb0 + Tc0)
By doing so, the thermal energy is corrected. At this time, time is allocated to Tb2, Tb0, and Tc0 in advance as weights according to the degree of influence of heat storage. In this way, the same processing is performed on all dots in one dot line, and these processing results are transferred to the thermal head by one history factor. That is, in order to print one line, as data to be applied to the same dot position on one line, in addition to the dot T0 to be printed, dots Ta, Tb1, Tb2, Tb0, Tc1 that constitute the history factor corresponding to the dot T0 are printed. , Tc2, Tc0, and Td are transferred to the thermal head a plurality of times (in the example of FIG. 6, nine times including the dot T0).

  FIG. 7 shows a configuration of a thermal history control device when the above-described thermal history control is performed by hardware using a dedicated circuit (external circuit or dedicated LSI).

  The conventional thermal history control device shown in FIG. 7 is connected to a thermal head 5 having a heating element 52 and a shift register 51, a thermal head interface LSI 4 connected to the thermal head 5, and the LSI 4 via a bus. CPU 1, ROM 2, and RAM 3. In this configuration, the history factor calculation processing is performed using the thermal history control circuit 44 provided in the LSI 4, and a mechanism for holding past print data is also provided in the thermal history control circuit 44. For this reason, the number of print lines that can be held as hardware is fixed, and the maximum number of history patterns that can be generated is limited. This becomes a great barrier when it becomes necessary to perform more accurate thermal history control, for example, by further increasing the printing speed. In addition, the hardware circuit scale becomes very large, leading to an increase in system cost.

  FIG. 8 shows a configuration of a thermal history control device when the above-described thermal history control is performed by software (see Patent Document 1).

  The conventional thermal history control device shown in FIG. 8 is connected to a thermal head 5 having a heating element 52 and a shift register 51, a thermal head interface LSI 4 connected to the thermal head 5, and the LSI 4 via a bus. CPU 1, ROM 2, and RAM 3. The print data storage area 31 in the RAM 3 stores dot images to be printed and dot images of past print lines from the previous one dot line to the previous four dot lines.

  The CPU 1 executes software 21 (software based on a history pattern generation algorithm described later) 21 stored in the ROM 2 to refer to the print data storage area 31 for each dot of a line to be printed from the past. Compares the past n lines for whether the corresponding dot on the print line or its adjacent dots on the left and right have been printed in the past, and prints “0” if the corresponding dot has been printed in the past. If not, the calculation is performed so that it is “1”. The calculation result is stored in the history pattern storage area 32. After all the calculations for the past n lines are completed, the calculation result corresponding to each history factor (hereinafter referred to as “history pattern”) is parallel / serial. Transfer to the conversion circuit 41. In parallel with this, by setting the time allocated to each history factor (hereinafter referred to as “history timer value”) to the timer circuit 42 each time, the generation timing of the data latch signal is adjusted. Perform temporal weighting.

  An example of the history pattern generation algorithm will be described with reference to FIGS. 9 and 10 illustrate a case where one dot line printed by the thermal head is composed of 640 dots (80 bytes).

  In FIG. 9, first, a history pattern corresponding to the dot Ta is generated among the history patterns corresponding to the dots Ta, Tb1, Tb2, Tb0, Tc1, Tc2, Tc0, and Td that constitute past history factors. The dot Ta is positioned at the immediately preceding dot Ta when viewed from the dot T0 to be printed. Accordingly, the dot data N for 32 dots (4 bytes) from the least significant bit side in the dot data N that will form the print data (N) to be printed from the print data storage area 31 and the print data for one dot line in the past. Of the dot row K1 for 640 bits, the dot row K1 for 32 dots from the least significant bit side is loaded into a calculation register (not shown) in the CPU 1. Next, it is determined whether or not each dot forming the dot row N for 32 dots is a printing dot. If it is a non-printing dot, the dot in the dot row Ta is set to data “0” and the printing dot is not used. For example, it is determined whether or not the dot row K1 at the same dot position as the dot row N is a print dot. If it is a print dot, the dot row Ta is not energized with data “0”. The column Ta is calculated to be energized data “1”. That is, in the dots at the same dot position in the two dot rows N and K1, if the dot row N is “1” and the dot row K1 is “0”, the dot row Ta is “1”, otherwise The dot row Ta becomes “0”.

  Next, the dot row Ta including the calculation results for the 32 dots is stored in the history pattern storage area 32. Thereafter, the same processing as described above is performed every 32 dots, and the number of times corresponding to one dot line is performed (20 times corresponding to 640 bits in the example of FIG. 9). As a result, a dot row Ta composed of the calculation results for 640 dots is formed as a history pattern corresponding to the dots Ta.

  Next, a history pattern corresponding to the dot Tb1 is generated. Since the dot Tb1 is located on the left side of the immediately preceding dot Ta when viewed from the dot T0 to be printed, the dot row K1 is shifted to the right by 1 bit as shown in FIG. The calculation is performed, and the calculation result is stored in the history pattern storage area 32. Thereafter, the same calculation is performed every 32 dots in the same manner as the dot row Ta described above, and the result is stored in the history pattern storage area 32, so that a dot consisting of a calculation result for 640 dots is obtained as a history pattern corresponding to the dot Tb1. A column Tb1 is formed.

  Next, since the dot Tb2 is positioned on the right side of the immediately preceding dot Ta in contrast to the dot Tb1, the dot row K1 is shifted to the left by 1 bit, and thereafter the same calculation as described above is performed. Thereafter, a history pattern is generated from the dot Tb0 to the dot Td by the same algorithm as described above. As a result, all the history patterns of dots Ta, Tb1, Tb2, Tb0, Tc1, Tc2, Tc0, and Td that constitute past history factors are generated.

  Thereafter, the history pattern is transferred to the parallel / serial conversion circuit 41 for each past history factor, and the history timer value for determining the application time for each history pattern is transferred to the timer circuit 42 when the transfer of one history pattern is completed. Set and wait for the application of the previous history factor being applied in parallel to end.

  After counting the set value, the timer circuit 42 notifies the head control signal generation circuit 43 of the count up. The head control signal generation circuit 43 receives a count up notification from the timer circuit 42 and outputs a data latch signal to the shift register 51 in the thermal head 5. The shift register 51 receives the data latch signal, latches the history pattern that has been shifted in until then, and drives the heating element 52 until the next data latch signal is received. In addition to the data latch signal, the head control signal generation circuit 43 also outputs an application permission signal for permitting driving of the heating element 52 and a shift clock signal necessary for actually shifting in the history pattern.

  FIG. 11 shows the above operation timing.

According to the conventional example described above, the history pattern generation processing is performed by software, so that the cost of the system can be reduced, and the processing that relied on the thermal history control circuit is processed by software, so that the performance of the microprocessor can be reduced. Theoretically, the history pattern can be generated infinitely except for the limitation of the physical application period, and more accurate thermal history control can be performed.
JP 2004-058447 A

  In the above-described conventional thermal history control device, the history pattern generation processing is changed from hardware generation using an external circuit or a dedicated LSI to software generation, thereby reducing the cost and increasing the accuracy of thermal history control as described above. 1) The next line history pattern is generated during one line printing time. 2) The printer control is performed by software multiple interrupts, and the multiple interrupts are performed within one line printing time. 3) There is a restriction that the occupied time of the CPU bus increases due to an increase in access to the thermal head interface LSI by DMA transfer from the RAM to the thermal head interface LSI within one line printing time.

  On the other hand, high-speed printing of multiple histories (multi-gradation) will be indispensable in this field. In this case, due to the above restrictions, in the worst case, within the printing time of one line of processing by software. It is also assumed that the next line history pattern generation process is not in time.

  The present invention was made in consideration of such a conventional situation, and while taking advantage of the history pattern generation of thermal history control using software, without increasing the hardware circuit scale as much as possible, The purpose is to enable high-speed printing of multiple histories.

  In order to achieve the above object, a thermal history control device according to the present invention includes a thermal head interface circuit connected to a drive circuit that drives a heating element in a thermal head, and a processor connected to the thermal head interface circuit. The processor has a dot position set in advance among dot line print data to be applied this time and dot line print data to be applied in the past in accordance with software based on a preset thermal history control algorithm. The print data forming the history pattern for each history factor is generated by comparing the print data forming the history factor corresponding to the history factor, and the thermal head interface circuit has a timer corresponding to a time allocated in advance for each history factor. A timer circuit for setting and counting the value, According to the timing based on the timer value counted by the circuit, the print data forming the history pattern of the history factor is transferred to the thermal head, thereby adjusting the application time of the print data of the dot line to be applied this time and A thermal history control device that performs thermal history control of a thermal head, wherein the timer circuit includes a plurality of first registers that individually set timer values for each of the history factors, and a predetermined number of the plurality of first registers. A second register for setting a history factor number for validating the first register of the first register, and the processor sets the history factor number before the start of application of print data of the dot line to be applied this time. In addition to being set in the second register, the history factor tag is added to the predetermined number of first registers that are enabled according to the set history factor number. The thermal head interface circuit counts the timer value set in the predetermined number of first registers by the timer circuit when printing the print data of the dot line to be applied this time. And transferring the print data forming the history pattern of the history factor to the thermal head according to the timing based on the counted timer value.

  In the present invention, the processor further includes a step of generating a history pattern for each history factor for the next dot line print data while applying the print data of the dot line to be applied this time. Also good.

  In the present invention, the print data forming the history pattern is data corresponding to energized dots in the print data of the dot line to be applied this time, and the print data forming the history factor is data corresponding to non-energized dots. Data corresponding to energized dots may be generated in some cases, and data corresponding to non-energized dots in other cases may be generated.

  In the present invention, the processor may be a CPU, and the thermal head interface circuit may be an integrated circuit connected to the CPU via a bus.

  The operation method of the thermal history control device according to the present invention includes a thermal head interface circuit connected to a drive circuit for driving a heating element in the thermal head, and a processor connected to the thermal head interface circuit, In accordance with software based on a preset thermal history control algorithm, the processor responds to dot positions set in advance among dot line print data to be applied this time and dot line print data applied in the past. The print data forming the history pattern is generated for each history factor by comparing with the print data forming the history factor, and the thermal head interface circuit sets a timer value corresponding to the time allocated in advance for each history factor. A timer circuit for counting, and the timer circuit A plurality of first registers for individually setting timer values for each history factor, and a second register for setting a history factor number for enabling a predetermined number of first registers among the plurality of first registers. And, according to the timing based on the timer value counted by the timer circuit, by transferring the print data forming the history pattern of the history factor to the thermal head, the application time of the print data of the dot line to be applied this time Is a thermal history control device for controlling the thermal history of the thermal head by adjusting the history factor before the start of application of dot line print data to be applied this time. In addition to being set in the second register, the history factor tag is added to the predetermined number of first registers that are enabled according to the set history factor number. When the print data of the dot line to be applied this time is printed, the thermal head interface circuit counts the timer value set in the predetermined number of first registers by the timer circuit, According to the timing based on the counted timer value, the print data forming the history pattern of the history factor is transferred to the thermal head.

  In the present invention, the processor may generate a history pattern for each of the history factors for the print data of the next dot line while applying the print data of the dot line to be applied this time.

  Furthermore, a thermal printer according to the present invention includes any one of the thermal history control devices described above and a thermal head connected to the thermal history control device.

  According to the present invention, it is possible to achieve high-speed printing of multiple histories without increasing the circuit scale of hardware as much as possible while taking advantage of the history pattern generation of thermal history control using software. .

  Next, the best mode for carrying out the thermal history control device, its operating method, and thermal printer according to the present invention will be described in detail with reference to the drawings. Note that the meanings of the terms “history factor”, “history pattern”, and “history timer value” used here are the same as those in the conventional example (Patent Document 1) described above, and the details thereof are omitted.

  The present embodiment is an improvement on the above-described conventional thermal history control device (see FIG. 8 to FIG. 11), and includes a print command transmitted from the host side of the POS device and the like, and Receives dot image data for the line to be printed, refers to past print dots according to the software based on the thermal history control algorithm stored in the ROM, generates a history pattern for each history factor, and based on the history pattern, the thermal history This is applied to a thermal printer that performs control.

  FIG. 1 is an overall configuration diagram of the thermal printer according to the present embodiment.

  The thermal printer shown in FIG. 1 includes a CPU 11, a communication control unit 12 connected to the CPU 11 via a bus, a ROM 13, a RAM 14, a thermal head interface LSI 15, a shift register 161 and a heating element 162 connected to the LSI 15. And a thermal head 16 having.

  The CPU 11 executes the software 131 stored in the ROM 13 to control the paper conveyance control and the paper cut control as a thermal printer, as well as the history for each history factor as in the conventional example (Patent Document 1) described above. Thermal history control including pattern generation processing (see FIGS. 9 and 10) is performed.

  The communication control unit 12 is connected to a host such as a POS device (not shown) and receives a print command and print data transmitted from the host.

  The ROM 13 stores software 131 executed by the CPU 11. The software 131 includes software based on the above-described thermal history control algorithm.

  The RAM 14 includes a print data storage area 141 and a history pattern storage area 142.

  The print data storage area 141 includes a dot image composed of dot row data of a predetermined number of dots (eg, 640 dots) to be printed from now on, and a dot image composed of dot row data of a plurality of past lines that have already been printed. Is retained.

  In the history pattern storage area 142, predetermined dots forming a history pattern of each history factor corresponding to the calculation result calculated according to the above-described thermal history control algorithm based on the past print data stored in the print data storage area 141. Print data composed of a number (for example, 640 dots) of dot rows is stored for each history factor.

  The thermal head interface LSI 15 performs operations associated with thermal history control including history pattern generation processing for each history factor in addition to control such as paper conveyance control and paper cut control as a thermal printer by the CPU 11. Specifically, the LSI 15 includes a parallel / serial conversion circuit 151, a timer circuit 152, and a head control signal generation circuit 153.

  The parallel / serial conversion circuit 151 converts parallel data (print data) of the bus interface sent from the communication control unit 12 via the bus into serial data, and outputs the serial data to the shift register 161 of the thermal head.

  The timer circuit 152 performs a timer count operation using a history timer value that is a time allocated to each history factor.

  The head control signal generation circuit 153 is a predetermined control signal to be given to the shift register 161 built in the thermal head 16 according to the operation timing generated by the timer circuit 152, that is, a data latch signal, an application permission signal, and a shift clock signal. Is generated.

  2A and 2B illustrate the internal configuration of the timer circuit 152 of the present embodiment as compared with the timer circuit 152 of the conventional example (Patent Document 1).

  The conventional timer circuit 42 shown in FIG. 2A counts the timer value setting register 421 for setting the timer value of each history factor, and the time set in the timer value setting register 422, and outputs the data latch signal. And a timer 422 for outputting.

  In contrast, the timer circuit 152 of the present embodiment shown in FIG. 2B has a plurality of (n) timer value setting registers 1522 (register 1, register 2, register for setting timer values individually for each history factor. 3,..., Register n) and how many history factors among a plurality of history factors are used, and how many of the timer value setting registers 1522 are to be enabled according to the number of factors. A factor number setting register 1521 to be set and a timer 1523 for counting the time set in the timer value setting register 1522 and outputting a data latch signal are provided. Compared to the conventional timer circuit 421 shown in FIG. 2A, there are a plurality of timer value setting registers 1522 for each history factor and a new factor number setting register 1521. It is different.

  Next, the operation of this embodiment will be described with reference to FIGS. 3 to 5 in comparison with the operation of the conventional example (Patent Document 1) shown in FIG.

  In the above-described conventional example (FIGS. 9 to 11), the case where dots Ta, Tb1, Tb2, Tb0, Tc1, Tc2, Tc0, and Td are used as past history factors for the dot T0 to be printed from now on. In this example, only the dots Ta, Tb1, and Tb0 are used (see FIG. 6). In this case, as one line of print data to be printed at the same dot position in one line of dot row, in addition to the print data of dot Ta to be printed (non-energized data “0” or energized data “1”), The print data (non-energization data “0” or energization data “1”) of the history pattern corresponding to the dots Ta, Tb1, and Tb0 that constitute the history factor is at the operation timing based on the history timer value assigned to each thermal head. 5 is transferred to the shift register 51 and printed via the heating element 52.

  First, the operation of the conventional example will be described with reference to FIGS.

  3 is an operation diagram showing the operation timing of the thermal head interface LSI of the conventional example shown in FIG. 8, and FIG. 4 is a case where the operation timing of the software by the CPU of the conventional example shown in FIG. FIG. Here, the application start signal, the data latch signal, and the application permission signal in FIGS. 3 and 4 correspond to control signals supplied from the head control signal generation circuit to the shift register.

  3 and 4, print data is sent from a host (not shown) and stored for each line in a print data storage area of the RAM. The CPU sets the history timer value in the timer value setting register of the timer circuit in the thermal head interface LSI by executing the software in the ROM, and transfers the print data for each line.

  At this time, the CPU executes the software to sequentially perform the pattern generation processing for the first line and the pattern generation for the n-th line, and at the same time, synchronize with each control signal (logic L level) of the application start and data latch signals. Then, a dummy timer value, which is the transfer time of Tb0, is set as a history timer value before application start when the pattern of the first line is generated, and corresponds to each history factor of Tb0, Tb1, Ta, T0 when the pattern of the nth line is generated Set the history timer value to be used. This is because the timer value setting register for setting the timer value has only one stage. The data latch signal is notified from the thermal head interface LSI to the CPU side by an interrupt signal or the like.

  Thereafter, on the thermal head interface LSI side, print data forming a dot line of one line is synchronized with each control signal (logic L level) of the data latch signal and the application permission signal within one line conveyance time starting from the start of application. In the order of Tb0, Tb1, Ta, and T0 that make up each history factor, each print data (history pattern print data) is transferred and latched to the shift register of the thermal head, and the heating element is selectively driven to print. Let the action take place.

  Therefore, in the conventional example, when the CPU executes software, a history pattern generation process for the n-th line data transferred from the host side within one line conveyance time, and a timer value set for each history factor, Are processed at the same priority, so in the case of high-speed printing, the one-line conveyance time is shortened and the load factor of the software is increased. In particular, in the case of multiple histories, the setting of the timer value for each history factor increases, the number of history patterns to be generated also increases, and the load factor of software increases. As a result, a limitation as a high-speed multi-history occurs.

  On the other hand, FIG. 5 is an operation diagram including the operation timing of the thermal head interface LSI 15 according to the present embodiment shown in FIG. 1 and the operation timing of the software 131 by the CPU 11.

  In the conventional example shown in FIG. 3 and FIG. 4 described above, only one timer value setting register for setting a timer value is provided, and therefore, it is assigned to Tb0, Tb1, Ta, and T0 that constitute each history factor before the start of application. The history timer value to be set cannot be set.

  On the other hand, in the present embodiment, the timer circuit 152 has a plurality of timer value setting registers 1522 for setting the timer value of each history factor, so that the timer values for all the history factors are set before the application is started. Is possible. In addition, since the factor number setting register 1521 is provided, the registers can be validated for the plurality of timer value setting registers 1522. Thereby, before starting the application, the CPU 11 side can grasp the timer value and the number of history factors of each history factor by executing the software 131.

  In FIG. 5, print data is sent from a host (not shown) and stored in the print data storage area 141 of the RAM 14 line by line. By executing the software 131 in the ROM 13, the CPU 11 sets the history factor number in the factor number setting register 1521 and sets the timer value of each history factor in the plurality of timer value setting registers 1522.

  Next, on the thermal head interface LSI 15 side, the timer circuit 152 is started in synchronization with a control signal (logic L level) corresponding to printing start.

  In the timer circuit 152, the timer value for each history factor is obtained from a plurality (n) of timer value setting registers 1522 (register 1, register 2, register 3,..., Register n) validated by the factor number setting register 1521. The set value is loaded into the timer 1523. The timer 1523 counts the loaded set value, and generates a data latch signal every time it counts up. At the same time, the set value of the timer value is loaded from the next timer value setting register 1522 and counted. This operation is repeated for all timer value setting registers 1522 enabled by the factor number setting register 1521.

  On the CPU 11 side, by executing the software 131, the history pattern generation processing for the first line is performed before starting the application, the timer value for each history factor is set in the timer value setting register, and the history factor number is set as the factor number. Set in the register 1521. Also, after the start of application, history pattern generation processing is preferentially performed for the nth line data transferred from the host side, and the timer value for each history factor of the nth line is set to the timer value setting register after the T0 transfer is completed. Then, the history factor number is set in the factor number setting register 1521.

  At this time, the data latch signal after application start generated on the thermal head interface LSI 15 side is not notified to the software 131 on the CPU 11 side. Thereby, on the CPU 11 side, the software 131 can preferentially perform the history pattern generation process without being obstructed by other signals. Therefore, the load factor of the software 131 during one line conveyance time becomes lower than that of the conventional example, the limitation that has occurred as the high-speed multi-history is eliminated, and high-speed multi-history can be achieved.

  Therefore, according to the present embodiment, the following effects can be obtained.

  1) Conventionally, interrupts corresponding to the number of history factors are notified to the software in one line, and the printing time for one line is shortened as the speed is increased. Therefore, the influence of the interrupt processing is increased as the speed is increased. On the other hand, in this embodiment, the software load can be reduced by reducing the interrupt processing that is software processing in one line.

  2) When the scale of the thermal head interface LSI is increased to realize high-speed and multi-history, the advantage of software generation is reduced. On the other hand, in the present embodiment, the history pattern is generated from hardware to software with only minor addition of register addition, and can be realized without increasing the scale of the thermal head interface LSI.

  3) In the present embodiment, the access to the thermal head interface LSI, which has been performed every time for the number of history factors, can be reduced, the software load is reduced, and the processing time and time for generating the history pattern from the next line are reduced. It becomes possible to spend the CPU bus. As a result, the time occupied by the CPU bus for printing and history control in one line can be reduced. Note that a decrease in the CPU bus occupation time in DMA transfer (RAM to thermal head interface LSI) can be easily dealt with by increasing the bus width.

  As described above, according to the present embodiment, in the history pattern generation process for each history factor with reference to the past print dots of the thermal printer, the history factor in one line is preliminarily set before starting the application of the line to be printed. By setting the number and each history timer value, the history timer values for the set history factors are sequentially expanded in the timer circuit, reducing the access to the thermal head interface LSI in one line, and several lines by software accordingly By performing the previous history pattern generation, it is possible to perform multi-history printing at higher speed printing. In other words, by providing a new history factor number register and a plurality of history timer value setting registers, the hardware performs the processing (setting the history timer value of the next history factor) that was previously performed by the software by counting up the timer circuit. By doing so, it is possible to greatly reduce the software processing in one line, and to generate history patterns from the next line.

  Note that the transfer order of the history pattern, the electrical logic of the application permission signal, and the number of history factors are applicable to the present embodiment and are not limited thereto. In the present embodiment, the case where only the thermal history control is performed has been described. However, the present embodiment is also applicable to the case where, for example, multi-gradation control (for example, see Japanese Patent Application Laid-Open No. 2004-255814) is performed.

  The present invention can be applied to the use of a thermal printer having a line-type thermal head mounted on a POS terminal or the like.

1 is a schematic block diagram illustrating an overall configuration of a thermal printer according to an embodiment of the present invention. (A) is a schematic block diagram which shows the internal structure of the timer circuit of a prior art example, (b) is a schematic block diagram which shows the internal structure of the timer circuit shown in FIG. It is a schematic timing chart explaining operation | movement of the heat history control apparatus of a prior art example. It is a schematic timing chart explaining the operation | movement of the heat history control apparatus of a prior art example with the operation | movement of software. It is a schematic timing chart explaining operation | movement of the thermal history control apparatus shown in FIG. It is a figure explaining the heat history control method of a prior art example. It is a schematic block diagram which shows the whole structure of the heat history control apparatus in the case of performing the heat history control of a prior art example with a hardware using a dedicated circuit. It is a schematic block diagram which shows the whole structure of the heat history control apparatus in the case of performing the heat history control of a prior art example using software. It is a figure explaining the log | history pattern generation | occurrence | production of the log | history factor by the heat log | history control apparatus shown in FIG. FIG. 10 is a diagram for explaining history factor history pattern generation by the thermal history control device shown in FIG. 8 following FIG. 9. It is a schematic timing chart explaining operation | movement of the heat history control apparatus shown in FIG.

Explanation of symbols

11 CPU
12 Communication control unit 13 ROM
14 RAM
15 thermal head interface 16 thermal head 131 software 141 print data storage area 142 history pattern storage area 151 parallel / serial conversion circuit 152 timer circuit 153 head control signal generation circuit 161 shift register 162 heating element 1521 factor number setting register 1522 timer value setting register 1523 timer

Claims (7)

A thermal head interface circuit connected to a drive circuit for driving a heating element in the thermal head;
A processor connected to the thermal head interface circuit,
In accordance with software based on a preset thermal history control algorithm, the processor responds to dot positions set in advance among dot line print data to be applied this time and dot line print data applied in the past. Compare the print data that constitutes the history factor and generate the print data that constitutes the history pattern for each of the history factors,
The thermal head interface circuit has a timer circuit for setting and counting a timer value corresponding to a time allocated in advance for each history factor,
According to the timing based on the timer value counted by the timer circuit, the print data forming the history pattern of the history factor is transferred to the thermal head, thereby adjusting the application time of the print data of the dot line to be applied this time. A thermal history control device for controlling thermal history of the thermal head,
The timer circuit sets a plurality of first registers that individually set a timer value for each history factor and a history factor number for enabling a predetermined number of first registers among the plurality of first registers. A second register;
The processor sets the history factor number in the second register before starting the application of the print data of the dot line to be applied this time, and the predetermined number that is validated according to the set history factor number The history factor timer value is individually set in the first register of
The thermal head interface circuit counts the timer value set in the predetermined number of first registers by the timer circuit when printing the print data of the dot line to be applied this time, and timing based on the counted timer value And transferring the print data forming the history pattern of the history factor to the thermal head.   2. The processor according to claim 1, wherein the processor generates a history pattern for each of the history factors for the next dot line print data while applying the print data of the dot line to be applied this time. Thermal history control device.   The print data forming the history pattern is energized dots when the print data of the dot line to be applied this time is data corresponding to energized dots and the print data forming the history factor is data corresponding to non-energized dots. The heat history control device according to claim 1 or 2, wherein the data is generated as data corresponding to a non-energized dot in other cases. The processor is a CPU;
4. The thermal history control device according to claim 1, wherein the thermal head interface circuit is an integrated circuit connected to the CPU via a bus. A thermal head interface circuit connected to a drive circuit for driving a heating element in the thermal head;
A processor connected to the thermal head interface circuit,
In accordance with software based on a preset thermal history control algorithm, the processor corresponds to dot line print data to be applied this time and dot positions set in advance among dot line print data to be applied in the past. Compare the print data that constitutes the history factor and generate the print data that constitutes the history pattern for each of the history factors,
The thermal head interface circuit has a timer circuit for setting and counting a timer value corresponding to a time allocated in advance for each history factor, and the timer circuit sets a timer value individually for each history factor. A plurality of first registers, and a second register for setting a history factor number for enabling a predetermined number of first registers among the plurality of first registers,
According to the timing based on the timer value counted by the timer circuit, the print data forming the history pattern of the history factor is transferred to the thermal head, thereby adjusting the application time of the print data of the dot line to be applied this time. An operation method of a thermal history control device for performing thermal history control of the thermal head,
The processor sets the history factor number in the second register before starting the application of dot line print data to be applied this time, and the predetermined number that is validated according to the set history factor number Individually setting the timer value of the history factor in the first register of
The thermal head interface circuit counts the timer value set in the predetermined number of first registers by the timer circuit when printing the print data of the dot line to be applied this time, and timing based on the counted timer value And transferring the print data forming the history pattern of the history factor to the thermal head.   The processor further includes a step of generating a history pattern for each of the history factors for the next dot line print data while applying the print data of the dot line to be applied this time. Item 6. The operation method of the thermal history control device according to Item 5. The thermal history control device according to any one of claims 1 to 4,
A thermal printer comprising a thermal head connected to the thermal history control device.

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